where is the label if review is positive or negative?

[Sandy4321]

where is the label if the review is positive or negative? we that they used it for sentiment supervised classification in this paper https://arxiv.org/abs/1509.01626 Character-level Convolutional Networks for Text Classification Xiang Zhang, Junbo Zhao, Yann LeCun and this https://arxiv.org/abs/1607.01759 Bag of Tricks for Efficient Text Classification Armand Joulin, Edouard Grave, Piotr Bojanowski, Tomas Mikolov